Abstract Background In-body wearable devices can protect workers’ health and safety. Moreover, they might provide data that could be capitalized on in the context of the European Health Data Space (EHDS), which aims at fostering a single market for medical devices and high-risk AI systems. Yet, neither EU legislation nor national law regulates the use of in-body wearables at the workplace and the related data protection and safety issues. This regulatory gap impacts on workers’ rights. Methods The study explores whether the EU regulatory framework used in the healthcare sector for medical devices could fit the in-body wearables’ application in employment. The legal and policy analysis takes the perspective of workers’ rights and discusses the application of a key GDPR principle: lawfulness. The research discusses the potential transformations in the EU health data protection framework that could close the regulatory gap. Results The EU regulatory framework for medical devices (focused on product safety, performance, and quality) is not equipped to address the data protection challenges linked to the use of in-body wearables for occupational health and safety purposes. The GDPR’s principle of lawfulness and the related guidance by EU and national data protection authorities lack clarity on employers’ possibilities to apply in-body wearables for occupational health purposes. Filling the regulatory gap is conducive to appropriate qualification and risk-based classification of in-body wearables, which affect pre- and post-market requirements and impact on data protection. Conclusions a. The EU legislator could use its social policy competence to regulate the use of in-body wearables to protect workers’ health while safeguarding their data. b. EU authorities should clarify whether and how the data collected by in-body wearables at the workplace could be shared and (re)used within the EHDS. c. Further input by data protection authorities is needed to close the regulatory gap. Key messages • The EU should regulate the use of in-body wearables to protect workers’ health and safety. • Health data gathered through the application of in-body wearables at the workplace may be an asset for the EHDS.